Videos

Respiratory Mucosa

During normal respiration, air travels through the nose, down the trachea, and into smaller and smaller airways called bronchi. Portions of the respiratory tract are lined with a mucous membrane, or mucosa. Specialized epithelial cells secrete mucus while other cells are covered in cilia. The mucus cleans and protects the air passages by trapping bacteria and debris while the cilia propel the mucus across the surface.